Merge pull request #2177 from asger-semmle/nodejs-detector-class-expression

Approved by max-schaefer

Author: semmle-qlci

javascript/extractor/src/com/semmle/js/parser/TypeScriptASTConverter.java

@@ -942,9 +942,7 @@ private Node convertClass(JsonObject node, String kind, SourceLocation loc) thro
     SourceLocation bodyLoc = new SourceLocation(loc.getSource(), loc.getStart(), loc.getEnd());
     advance(bodyLoc, skip);
     ClassBody body = new ClassBody(bodyLoc, convertChildren(node, "members"));
-    if ("ClassExpression".equals(kind) || id == null) {
-      // Note that `export default class {}` is represented as a ClassDeclaration
-      // in TypeScript but we treat this as a ClassExpression.
+    if ("ClassExpression".equals(kind)) {
       ClassExpression classExpr =
           new ClassExpression(loc, id, typeParameters, superClass, superInterfaces, body);
       attachSymbolInformation(classExpr.getClassDef(), node);
@@ -967,7 +965,13 @@ private Node convertClass(JsonObject node, String kind, SourceLocation loc) thro
       classDecl.addDecorators(convertChildren(node, "decorators"));
       advanceUntilAfter(loc, classDecl.getDecorators());
     }
-    return fixExports(loc, classDecl);
+    Node exportedDecl = fixExports(loc, classDecl);
+    // Convert default-exported anonymous class declarations to class expressions.
+    if (exportedDecl instanceof ExportDefaultDeclaration && !classDecl.getClassDef().hasId()) {
+      return new ExportDefaultDeclaration(
+          exportedDecl.getLoc(), new ClassExpression(classDecl.getLoc(), classDecl.getClassDef()));
+    }
+    return exportedDecl;
   }
 
   private Node convertCommaListExpression(JsonObject node, SourceLocation loc) throws ParseError {

javascript/extractor/tests/ts/input/exportclass.ts

@@ -0,0 +1 @@
+export class {}

javascript/extractor/tests/ts/output/trap/exportclass.ts.trap

@@ -0,0 +1,114 @@
+#10000=@"/exportclass.ts;sourcefile"
+files(#10000,"/exportclass.ts","exportclass","ts",0)
+#10001=@"/;folder"
+folders(#10001,"/","")
+containerparent(#10001,#10000)
+#10002=@"loc,{#10000},0,0,0,0"
+locations_default(#10002,#10000,0,0,0,0)
+hasLocation(#10000,#10002)
+#20000=@"global_scope"
+scopes(#20000,0)
+#20001=@"script;{#10000},1,1"
+#20002=*
+lines(#20002,#20001,"export class {}","
+")
+#20003=@"loc,{#10000},1,1,1,15"
+locations_default(#20003,#10000,1,1,1,15)
+hasLocation(#20002,#20003)
+numlines(#20001,1,1,0)
+#20004=*
+tokeninfo(#20004,7,#20001,0,"export")
+#20005=@"loc,{#10000},1,1,1,6"
+locations_default(#20005,#10000,1,1,1,6)
+hasLocation(#20004,#20005)
+#20006=*
+tokeninfo(#20006,7,#20001,1,"class")
+#20007=@"loc,{#10000},1,8,1,12"
+locations_default(#20007,#10000,1,8,1,12)
+hasLocation(#20006,#20007)
+#20008=*
+tokeninfo(#20008,8,#20001,2,"{")
+#20009=@"loc,{#10000},1,14,1,14"
+locations_default(#20009,#10000,1,14,1,14)
+hasLocation(#20008,#20009)
+#20010=*
+tokeninfo(#20010,8,#20001,3,"}")
+#20011=@"loc,{#10000},1,15,1,15"
+locations_default(#20011,#10000,1,15,1,15)
+hasLocation(#20010,#20011)
+#20012=*
+tokeninfo(#20012,0,#20001,4,"")
+#20013=@"loc,{#10000},2,1,2,0"
+locations_default(#20013,#10000,2,1,2,0)
+hasLocation(#20012,#20013)
+toplevels(#20001,0)
+#20014=@"loc,{#10000},1,1,2,0"
+locations_default(#20014,#10000,1,1,2,0)
+hasLocation(#20001,#20014)
+#20015=@"module;{#10000},1,1"
+scopes(#20015,3)
+scopenodes(#20001,#20015)
+scopenesting(#20015,#20000)
+isModule(#20001)
+isES2015Module(#20001)
+#20016=*
+stmts(#20016,30,#20001,0,"export class {}")
+hasLocation(#20016,#20003)
+stmtContainers(#20016,#20001)
+#20017=*
+stmts(#20017,26,#20016,-1,"class {}")
+#20018=@"loc,{#10000},1,8,1,15"
+locations_default(#20018,#10000,1,8,1,15)
+hasLocation(#20017,#20018)
+stmtContainers(#20017,#20001)
+#20019=*
+properties(#20019,#20017,2,0,"constructor() {}")
+#20020=@"loc,{#10000},1,6,1,5"
+locations_default(#20020,#10000,1,6,1,5)
+hasLocation(#20019,#20020)
+#20021=*
+exprs(#20021,0,#20019,0,"constructor")
+hasLocation(#20021,#20020)
+enclosingStmt(#20021,#20017)
+exprContainers(#20021,#20001)
+literals("constructor","constructor",#20021)
+#20022=*
+exprs(#20022,9,#20019,1,"() {}")
+hasLocation(#20022,#20020)
+enclosingStmt(#20022,#20017)
+exprContainers(#20022,#20001)
+#20023=*
+scopes(#20023,1)
+scopenodes(#20022,#20023)
+scopenesting(#20023,#20015)
+#20024=@"var;{arguments};{#20023}"
+variables(#20024,"arguments",#20023)
+isArgumentsObject(#20024)
+#20025=*
+stmts(#20025,1,#20022,-2,"{}")
+hasLocation(#20025,#20020)
+stmtContainers(#20025,#20022)
+isMethod(#20019)
+#20026=*
+entry_cfg_node(#20026,#20001)
+#20027=@"loc,{#10000},1,1,1,0"
+locations_default(#20027,#10000,1,1,1,0)
+hasLocation(#20026,#20027)
+#20028=*
+exit_cfg_node(#20028,#20001)
+hasLocation(#20028,#20013)
+successor(#20022,#20019)
+#20029=*
+entry_cfg_node(#20029,#20022)
+hasLocation(#20029,#20020)
+#20030=*
+exit_cfg_node(#20030,#20022)
+hasLocation(#20030,#20020)
+successor(#20025,#20030)
+successor(#20029,#20025)
+successor(#20021,#20022)
+successor(#20019,#20017)
+successor(#20017,#20028)
+successor(#20026,#20016)
+numlines(#10000,1,1,0)
+filetype(#10000,"typescript")